My spaces (I don’t have booths, it’s more open) are about 2.4×2.4 meters which works fine, but keep in mind that you need to also add in arm room. Just because there’s a chaperone system doesn’t mean the customer will honor it, but the extra space around helps when they get to to and are still swinging their arms around, so the 3×3 of your spaces will probably be smaller than that for the actual play sapce. As far as height, I think 2.4 is fine, but remember that if a taller person comes in (we’ll say 6′ or more), the may reach up and you have to figure how much higher than their head (plus about 4 inches for the controller) they might reach.

I have my cables hanging from the ceiling with keychain pulls. My space came with an exposed artsy drop ceiling that helps hod things in place. My ceiling is just over 8′ (2.4m) high and it does get hit sometimes, but usually it’s if a taller person jumping.